Initial import

1 files changed, 190 insertions, 0 deletions

diff --git a/arch/arm/mach-omap1/fpga.c b/arch/arm/mach-omap1/fpga.c
new file mode 100644
index 000000000..3c0e42219
--- /dev/null
+++ b/arch/arm/mach-omap1/fpga.c
@@ -0,0 +1,190 @@
+/*
+ * linux/arch/arm/mach-omap1/fpga.c
+ *
+ * Interrupt handler for OMAP-1510 Innovator FPGA
+ *
+ * Copyright (C) 2001 RidgeRun, Inc.
+ * Author: Greg Lonnon <glonnon@ridgerun.com>
+ *
+ * Copyright (C) 2002 MontaVista Software, Inc.
+ *
+ * Separated FPGA interrupts from innovator1510.c and cleaned up for 2.6
+ * Copyright (C) 2004 Nokia Corporation by Tony Lindrgen <tony@atomide.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+
+#include <mach/hardware.h>
+
+#include "iomap.h"
+#include "common.h"
+#include "fpga.h"
+
+static void fpga_mask_irq(struct irq_data *d)
+{
+	unsigned int irq = d->irq - OMAP_FPGA_IRQ_BASE;
+
+	if (irq < 8)
+		__raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO)
+			      & ~(1 << irq)), OMAP1510_FPGA_IMR_LO);
+	else if (irq < 16)
+		__raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI)
+			      & ~(1 << (irq - 8))), OMAP1510_FPGA_IMR_HI);
+	else
+		__raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2)
+			      & ~(1 << (irq - 16))), INNOVATOR_FPGA_IMR2);
+}
+
+
+static inline u32 get_fpga_unmasked_irqs(void)
+{
+	return
+		((__raw_readb(OMAP1510_FPGA_ISR_LO) &
+		  __raw_readb(OMAP1510_FPGA_IMR_LO))) |
+		((__raw_readb(OMAP1510_FPGA_ISR_HI) &
+		  __raw_readb(OMAP1510_FPGA_IMR_HI)) << 8) |
+		((__raw_readb(INNOVATOR_FPGA_ISR2) &
+		  __raw_readb(INNOVATOR_FPGA_IMR2)) << 16);
+}
+
+
+static void fpga_ack_irq(struct irq_data *d)
+{
+	/* Don't need to explicitly ACK FPGA interrupts */
+}
+
+static void fpga_unmask_irq(struct irq_data *d)
+{
+	unsigned int irq = d->irq - OMAP_FPGA_IRQ_BASE;
+
+	if (irq < 8)
+		__raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) | (1 << irq)),
+		     OMAP1510_FPGA_IMR_LO);
+	else if (irq < 16)
+		__raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI)
+			      | (1 << (irq - 8))), OMAP1510_FPGA_IMR_HI);
+	else
+		__raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2)
+			      | (1 << (irq - 16))), INNOVATOR_FPGA_IMR2);
+}
+
+static void fpga_mask_ack_irq(struct irq_data *d)
+{
+	fpga_mask_irq(d);
+	fpga_ack_irq(d);
+}
+
+static void innovator_fpga_IRQ_demux(unsigned int irq, struct irq_desc *desc)
+{
+	u32 stat;
+	int fpga_irq;
+
+	stat = get_fpga_unmasked_irqs();
+
+	if (!stat)
+		return;
+
+	for (fpga_irq = OMAP_FPGA_IRQ_BASE;
+	     (fpga_irq < OMAP_FPGA_IRQ_END) && stat;
+	     fpga_irq++, stat >>= 1) {
+		if (stat & 1) {
+			generic_handle_irq(fpga_irq);
+		}
+	}
+}
+
+static struct irq_chip omap_fpga_irq_ack = {
+	.name		= "FPGA-ack",
+	.irq_ack	= fpga_mask_ack_irq,
+	.irq_mask	= fpga_mask_irq,
+	.irq_unmask	= fpga_unmask_irq,
+};
+
+
+static struct irq_chip omap_fpga_irq = {
+	.name		= "FPGA",
+	.irq_ack	= fpga_ack_irq,
+	.irq_mask	= fpga_mask_irq,
+	.irq_unmask	= fpga_unmask_irq,
+};
+
+/*
+ * All of the FPGA interrupt request inputs except for the touchscreen are
+ * edge-sensitive; the touchscreen is level-sensitive.  The edge-sensitive
+ * interrupts are acknowledged as a side-effect of reading the interrupt
+ * status register from the FPGA.  The edge-sensitive interrupt inputs
+ * cause a problem with level interrupt requests, such as Ethernet.  The
+ * problem occurs when a level interrupt request is asserted while its
+ * interrupt input is masked in the FPGA, which results in a missed
+ * interrupt.
+ *
+ * In an attempt to workaround the problem with missed interrupts, the
+ * mask_ack routine for all of the FPGA interrupts has been changed from
+ * fpga_mask_ack_irq() to fpga_ack_irq() so that the specific FPGA interrupt
+ * being serviced is left unmasked.  We can do this because the FPGA cascade
+ * interrupt is run with all interrupts masked.
+ *
+ * Limited testing indicates that this workaround appears to be effective
+ * for the smc9194 Ethernet driver used on the Innovator.  It should work
+ * on other FPGA interrupts as well, but any drivers that explicitly mask
+ * interrupts at the interrupt controller via disable_irq/enable_irq
+ * could pose a problem.
+ */
+void omap1510_fpga_init_irq(void)
+{
+	int i, res;
+
+	__raw_writeb(0, OMAP1510_FPGA_IMR_LO);
+	__raw_writeb(0, OMAP1510_FPGA_IMR_HI);
+	__raw_writeb(0, INNOVATOR_FPGA_IMR2);
+
+	for (i = OMAP_FPGA_IRQ_BASE; i < OMAP_FPGA_IRQ_END; i++) {
+
+		if (i == OMAP1510_INT_FPGA_TS) {
+			/*
+			 * The touchscreen interrupt is level-sensitive, so
+			 * we'll use the regular mask_ack routine for it.
+			 */
+			irq_set_chip(i, &omap_fpga_irq_ack);
+		}
+		else {
+			/*
+			 * All FPGA interrupts except the touchscreen are
+			 * edge-sensitive, so we won't mask them.
+			 */
+			irq_set_chip(i, &omap_fpga_irq);
+		}
+
+		irq_set_handler(i, handle_edge_irq);
+		set_irq_flags(i, IRQF_VALID);
+	}
+
+	/*
+	 * The FPGA interrupt line is connected to GPIO13. Claim this pin for
+	 * the ARM.
+	 *
+	 * NOTE: For general GPIO/MPUIO access and interrupts, please see
+	 * gpio.[ch]
+	 */
+	res = gpio_request(13, "FPGA irq");
+	if (res) {
+		pr_err("%s failed to get gpio\n", __func__);
+		return;
+	}
+	gpio_direction_input(13);
+	irq_set_irq_type(gpio_to_irq(13), IRQ_TYPE_EDGE_RISING);
+	irq_set_chained_handler(OMAP1510_INT_FPGA, innovator_fpga_IRQ_demux);
+}